A common but effective submachine gun. Fires three-round bursts, and can be pulsed for a higher rate of fire at the expense of accuracy. Very effective against shields and biotic barriers.

As kinetic barriers have grown in popularity, so has the popularity of submachine guns. Manufactured by the Elkoss Combine, the Shuriken Machine Pistol has a reputation for being deadly and easy to use, but is weak against armor.

Unlike the M-9 Tempest, the Shuriken is not fully-automatic but fires in three-round bursts. This quality, combined with its more manageable recoil, makes the Shuriken slightly better at long range shooting than the M-9 Tempest, but its fire rate and damage rate leave a lot to be desired.

The Shuriken has a hidden feature: it can maintain a constant rate of fire if the trigger button is pressed quickly and repeatedly.

This weapon is very effective on squadmates, particularly prior to acquiring the Locust - they do not suffer accuracy reductions due to recoil, allowing them to land virtually every shot. In addition, the burst fire of the Shuriken forces your squad to drop back into cover more frequently, keeping them alive longer on higher difficulty levels.

While the M-4 Shuriken suffers from the main drawback of not being able to fire on full-auto with conventional means and poor accuracy; it still has the second highest damage and RoF per shot for any SMG, allowing it to deal better burst DPS at close range than the slow-firing Locust, and is quite controllable while firing at full-auto, by quick-tapping the fire button, at ranges where the Tempest would start to lose precision when firing at full auto. Overall, the Shuriken pistol middles between the precision and power of the M-12 Locust and the bulletstorm-esque firing rate of the M9 Tempest.

Commander Shepard is seen using the Shuriken in a number of cutscenes even if Shepard's class is a Soldier, which cannot use submachine guns. It appears to be the default handgun of Mass Effect 2. In cutscenes it can be seen in the hands of non-combatant NPCs and squad members, regardless of what SMG they're wielding or weapons training they have. It is also seen in Jack's "quarters".

The Shuriken should be considered a type of machine pistol due to its compact size and rapid burst fire, similar in nature to a Beretta 93R.